<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>ECharts使用步骤</title>
    <style>
        .a {
            width: 0px;
            height: 0px;
            border-left: 150px solid red;
            border-top: 150px solid #fff;
            border-bottom: 150px solid #fff;
        }
    </style>
</head>
<body>
   <div class="a">
   </div>
    
</body>
</html>